1) Assign posts to appropriate Categories. You can make multiple Categories and even sub categories. In most skins, there appears a link to the current Category, so all posts of the particular topic are shown.

2) This is done by so called stub files. I refer to the [url=http://manual.b2evolution.net/Stub_file]manual[/url]. If you have subsequent questions, don't hesitate to ask.

Good luck

I've done, but is a bit hackish.

You can see a example at:

http://b2evolution.waltercruz.com/b2evolution_1_10_lancado#comments

what I have done:
I use innodb tables - what means no fulltext index.
I have a python script that I run after each posting. The script create a temporary table with my posts contents, creates a fulltext index on it and make the search. So, i have a table called items_related that looks like:

|item| item_related|

I insert 5 items relateds to each table.

As I said, is a bit hackish

[]'s
- Water